Boiler-flue.



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UNI-TED sfrix'rns PATENT onirica.

BQILER-FLUE,

Specification of LettersPatent.

PatentedL June 19, 1906.

Appunti@ fumi imma, 190e. serai No. 306,157.

Tual wil/0m, it muy concern:

Be it known that I, ALnIN VAN. WALTERS, a

citizen of the UnitedStates, and a residentv of,

Thisinvention relates to flues or tubes as constructed 1n modern tubular bollers, and 1sespeciallv useful in connection with steamboilers ofthe locomotive `or marine type.

The object of the invention is to provide a strong, efficient, and durable holler-tube which `effects a lasting and,l hermetically-'tight joint between the tubey and the fluesheets,'

which can be easil removed. and replaced 'whenworn out, an which tends to decrease the troublesome encrustatlon encountered in steam-boilers. l e

The invention consists in the construction and combination of parts, which will-be set forth hereinafter, and particularly pointed out in the claims. i

Reference is to be had to the accompanying drawings, which illustrate as lan, example the preferred embodiment of my invention, in which drawings similar characters of reference indicate like parts in the several views, and in which- Figure 1 is a longitudinal cross-section of my invention with a` portion broken away. Fig. 2is an elevation of that part of the tube which fits into the back Hue-sheet; and- Fi 3 is aninner view of a portion of the bac flue-sheet, showing the opening for the end of the tube.

Referring more particularly to the drawings, 1 representsl the front and 2 the back flue-sheet of a boiler. The flue ,or boi1er tube 3, (shown partially broken awa in the drawings,) is securedy in'orifices in t e fluev sheets and permits the passage of the gases of the smoke box.

combustion from the combuStien-chamber to The tube 3 near its rear extremity is provided with an external annular flange 4, disposed concentrically around the flue-body and having a rounded rim 5.

This rim 5 isprovided internally and externally with threads 6 and 7, which are adapted to engage with corresponding threads 9 and 10 ina circular recess or groove 8, formed in the back yflue-sheet 2 around an orifice 11 for the flue. The forward end l2 of the tube flares or widens outwardly to 'al diameter slightly reater thanthat of the extension 4, so that t e latter-willpassgthrough the orifice for this larger end of 'the tube in the front flue-sheet, thus ermitting the putting in placeV or removal) of the flue through this opening;

In placing the tube in the boiler it is inserted 'through the opening in the front fluesheet andthe rear end is inserted in the korifice drilled for thisv purpose in the back fluesheet.l The threaded rim of the shoulder 4 is then tightly screwed into the recess 8 and the end' 12 of the tube is expanded and turned over into a beadl 13 in the usual manner. The forward outwardly-tapered end 14 of the tube is secured in the opening in the front flue-sheet by the known method of` expanding y and turning the end over into a bead 15.

As the gases of. combustion are at the highest temperature on entering' the tubes from thel combustion-chamber, the ends of the tubes which first come in contact with the gases are more liable to injury therefrom. Consequently the reinforcement provided by the threaded shoulder 4 is of great value, and even should the bead 13 be burned ofl there would be no leakage around the end' of i the tube, as the rim '6 of the extension 4 forms a tight joint withv the threaded groove 8. There is-no danger of burning out this joint, as the shoulder 4 is at all times surrounded by water. In using boiler-tubes of this type the spacingwill be greater, and as thetubes will consequently be farther apart the accumulation ofencrustations Will be retarded.

Having thus described the preferredV embodiment ofl my invention, what I claim as new, and desire to secure by Letters Patent,

1, A boiler-flue comprising a tubular body having an annular concentric flange near one end, means for securlng sald flange to the `inner side of the flue-sheet, and extremities adapted to attach in openings in the fluesheets.

2. A boiler-flue comprising a tubular body having an annular concentric flange near one end provided with a threaded rim adapted to engage with a threaded'l groove in the fluesheet, and extremities adapted to be expandedwin openings in the flue-sheets.

3. A boiler-flue comprising a tubular body, an exterior concentric flange having an annular rim provided externally and internally with screw-threads adapted to engage with a correspondingly-threaded.groove in the fluesheet, and extremities `adapted to be expanded in openings,inV the flue-sheets.

IOO

body, an annular flange near one end having a threaded rim adapted to engage with said groove, and extremities panded in said openings.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALDIN VAN. WALTERS.

Witnesses:

P. A. FRANKs, PHILIP SCHULER.

adapted to be exx5 

